When processing parts through successive treatment stations such as cleansing baths, anodizing, or alodine baths, rinses, painting chambers and baking ovens, it is common practice to rack and rerack the parts several times for the various sequential operations. Such multiple handling of parts is not cost effective and involves some increased risk for both the parts and the handlers. Furthermore, current practice involves the use of virtually as many different racking clips as there are sizes and shapes of parts. This further adds to the cost and inefficiency of the operation since these many different racking clips must be inventoried and replenished as necessary.
It is the purpose of the racking equipment of the present invention to provide racking clips that provide a system with sufficient flexibility that the different number of racking clips can be significantly reduced. Further, it is the object of this invention to provide a racking system permitting the parts to be racked a single time and conveyed through any number of operations without the need for removal and reracking. To accomplish these objectives, the racking clips must be designed to mask or shadow as little of the parts as possible. Further, parts to be painted must present the two opposing surfaces in such a manner that adjacent parts will not mask or shadow any portion of those opposing surfaces.
Each of the clips of the family disclosed herein comprises a first set of article-engaging fingers for contacting a first edge of an article, and a second set of article-engaging fingers for engaging a second edge of a second article. Some form of spring, preferably a torsional spring, biases at least one set of article-engaging fingers toward another so as to grip the article therebetween. A spring clamp is associated with the article-engaging fingers for movably securing the fingers to a support member which is used to transport articles from station to station. This repositionability feature of the spring clamp provides the system the flexibility necessary to accommodate different sizes and shapes of parts. In each embodiment at least one of either the second set of article-engaging fingers and/or the spring clamp is mounted on a member separate from its corresponding first set of article-engaging fingers.
In a first preferred embodiment of the mounting clips of the present invention, a generally U-shaped first portion has it's base secured to the base of a generally V-shaped second portion. The U-shaped first portion has a base which defines a longitudinal axis and can be constructed of rod or sheet stock, although for some applications, particularly those involving salt baths, the rod stock is preferred. In the rod stock embodiment, two U-shaped first portions are used with each mounting clip. The generally V-shaped second portion has a flattened base which defines a longitudinal axis which is perpendicular to the axis of the U-shaped member and is connected to the base of the U-shaped first portion(s). Projecting laterally outwardly from the upturned arm of each U-shaped first portion, as determined relative to the longitudinal axis of the U-shaped portion, is a generally C-shaped set of article-engaging fingers which receive the edge of an article therebetween. The article-engaging fingers on adjacent mounting clips engage opposite edges of the same article. The V-shaped second portions, which form the spring clamps for engaging the support, will be positioned along that support so that the sets of article-engaging fingers are separated by a distance which is less than the pertinent dimension of the article. In this way, the finger sets are each torqued outwardly and grip the article with torsional spring pressure.
In a second preferred embodiment, a first set of article-engaging fingers are interconnected to a second article-engaging member by means of a spring member. This spring member which is preferably a torsional spring, may comprise a coil spring with the coil being affixed as by welding, or the like, to a laterally extending support bar. The lateral support bar may be adjusted relative to the vertical support to vary the size of parts the system can accommodate. In fact, different rows can accommodate parts of different lengths. The first set of article-engaging fingers of a first mounting clip cooperates with a second article-engaging member of a second mounting clip. For standard width articles, a plurality (at least two) pairs of mounting clips will cooperate to secure the article. Each second member including a camming shoulder and a V-shaped notch so the article can be inserted against the pressure of the spring member, camming the second member upwardly until the upper edge of the article engages in and is captured by the V-shaped notch. For narrow articles which are engaged by a single pair of cooperating mounting clips, the second member is modified by a pair of stabilizing fingers adjacent the V-shaped notch opposite the camming shoulder, which engage the back surface of the part and prevent its working loose from the mounting clips.
The ends of the laterally extending support bars may be secured to the vertical supports by a bar retainer clip on each end (and, if necessary, on intermediate supports, as well). The bar retainer clip includes a spring clamp of the same general nature as the first embodiment of mounting clips and one of a variety of shapes of clip members. In one embodiment, the clip member is U-shaped and clamps the bar between the two arms of the U. In another embodiment, the clip member is L-shaped and clasps the bar against the base of the spring clamp. In yet a third embodiment, the clip member captures the end of the lateral support bar between itself and the vertical support member to which it is secured. A stop tab may be provided to any of the three embodiments to prevent the bar from walking upwardly out of the grasp of the retainer clip or becoming skewed as the result of one end moving upwardly relative to the other.
Yet a third preferred family of mounting clips incorporates a V-shaped spring clamp for engaging a support bar and two identical pairs of article-engaging fingers employing C-shaped finger sets welded thereto. In one embodiment, a rod member forms a coil spring for each of two finger sets and is interconnected below the bottom of one arm of the spring clamp with a second such arrangement provided on the opposite spring clamp arm which engages a different article than the first. In a second embodiment of this family of mounting clips, the two sets of fingers are interconnected across the base of the V-shaped clamp rather than across the bottom of each arm.
It is an important aspect of the present invention that the spring clamp means form solid electrical contact with the support upon which it is mounted as well as the article-engaging fingers or members which are affixed to the spring clamp means and that the article-engaging fingers of the present invention have solid electrical contact with the article supported thereby. Both the anodizing process and the painting step require an electrical charge to be transmitted through the carrier support through the mounting clips to the articles being treated.